interest当文中是总体来讲兴趣、利益的时候,用复数。比如one should not look after one's own interests。当就某一个事物的兴趣,就单数拉。 he lost his interest in math.hear about 和hear of 都有听说的意思。基本上一样。unable是说没有能力,he is unable to walk。 而impossible是不可能,it is impossible to let him walk. 他们都是形容词,用法基本相同,但词义相差很多。each 可以直接做代词单独使用,every不可以。i have two books, each is